Alloys



Patented Sept. 14, 1943 ALLOYS Reginald S. Dean and Clarence T. Anderson, Salt Lake City, Utah, assignors to Chicago Development Company, Chicago, 111., a corporation of Illinois No Drawing. Application October 20, 1941, Serial No. 415,769

6 Claims.

Our invention relates to the preparation of alloys having good corrosion resistance under atmospheric conditions as well as with respect to attack by acids under oxidizing conditions.

The alloys to which our invention relates contain from'about 3% to about 12% aluminum,

from about 45% to about 75% iron, balance substantially all manganese, the manganese constituting at least 20% of the alloy. A preferred embodiment of our invention encompasses alloys containing from about 20% to about 50% manganese, from about to about aluminum, balance substantially all iron. We have found that when these alloys are made from electrolytic manganese of high purity, preferably at least 99.0% pure and especially at least'99.9% pure, and commercially pure forms of iron and aluminum, they are ductile and may be readily rolled and drawn into wire.

The following table shows a number of illustrative alloys made in accordance with our present invention and wherein various of the properties of the said alloys are listed. In the table, He means Rockwell C scale; Rb means Rockwell B scale; C. W. means cold worked; S. C. means slow cooled; and Q means quenched.

course, that the anodized alloys should not be used under conditions where the anodic film would be abraded away. The film or coating may substantially all iron, the iron constituting from be placed upon the alloy by the well known socalled anodizing process; that is, by making the alloys the anode of an electrical circuit in a suitable electrolyte.

We have also found that, in certain cases, the alloys of our present invention may be employed for various purposes, particularly for use as electrical heating elements, by incorporating small amounts of chromium and/or silicon, about 1% to about 2% of either or both chromium and silicon being effective in most cases.

What we claim as new and desire to protect.

by Letters Patent of the United States is:

1. Alloys, having good ductility and corrosion resistance properties, containing from 3% to 12% aluminum, from 45% to 75% iron, balance substantially all manganese, the manganese constituting at least 20% of the alloy.

2. Alloys, having good ductility and corrosion resistance properties, containing from 5% to 10% aluminum, from 20% to 50% manganese, balance substantially all iron, the alloy being made from No. Comp. Ductility Hardness as out Hardness C. W. 251 Expansion Resistivity B. 0. 000 C. Q 900 C.

1 Mn20 Brittle on cold Rc+8 Re 0 Al 10 work. (magnetic) (fairly magnetic) Fe .70 2 Mn20 Ductilenns.-. Rb+5 Rel-2 13. 21x10 101. 8X10" lielib-Hi0 $1 2 (slightly magnetic) (slightly magnetic) Rb+52 (non-magnetic) e 3 M1150 Ductile..-;. Bil-28 Rc+10 7. 67x10" 120.9x1olie-33 Rc-21 %1 g (non-magnetic) (non-magnetic) (non-magnetic) ately high temperatures. We have found, however, that by anodizing the alloys we can coat them with a continuous film of aluminum oxide which makes them exceedingly resistant to atmospheric corrosion and acid corrosion. Indeed, they appear to withstand the action of dilute acids better thanstainless steel. Anodized wires made of the alloys of the present invention are somewhat better with regard to their scaling at high temperatures than is the case of the nonanodized products. It will be understood, oi

40 aluminum, manganese, and iron of high purity.

3. Alloys, having good ductility and corrosion resistance properties, containing from 5% to 10% aluminum, from 20% to 50% electrolytic manganese having a purity of at least 99.0%, balance to of the alloy.

4. An alloy, having good ductility and corrosion resistance properties, containing about 5% aluminum, about 50% manganese, and about 45% iron.

5. Anodized alloys having good ductility and corrosion resistance properties, containing from 3% to 12% aluminum, from 45% to 75% iron, balance substantially all manganese, the manganese constituting at least 20% of the alloys.

6. Anodized alloys, having good ductility and corrosion resistance properties, containing from 5% to 10% aluminum, from 20% to 50% manganese, balance substantially all iron.

REGINALD S. DEAN. CLARENCE T. ANDERSON. 

